Existential (adjective)

1. Relating to existence, especially human existence and the meaning and purpose of life.
2. Relating to or characteristic of existentialism.

Origin:

Mid 19th century: from french existentiel or german existenziell, from existentiell "essential", from existentie "existence" + -ell.

Examples:

1. The novel dealt with existential themes of meaning and purpose.
2. He had an existential crisis and was questioning the purpose of his life.
3. The play was an existential comedy.
4. The topic of the meeting was existential threat to our planet.
5. The movie explored the existential questions of human existence.